Utilisation de la fonction d'enveloppement pour créer une came de baril

Article by Alin Vargatu, CSWE updated August 21, 2012

Article

Modélisons ensemble une came de baril. Regardez d'abord cette vidéo :


The inspiration for this tech tip came from the SolidWorks Forum, where Danail Lesev was asking for help in creating a barrel cam.

The description of the cam profile is shown in fig. 1.

Fig. 1 Barrel Cam Profile

He used the correct tool for debossing the cam – the Wrap Feature, but his attempts to create the cam were not satisfactory, see fig. 2.

Fig. 2 Created CAM

Fig. 2 Created CAM

The reason for that lies inside the sketch to be wrapped (fig. 3). First of all, the overall length of the sketch has to be equal to the circumference of the cylinder (55 x π); otherwise the cam will not “close around the cylindrical body. There is also a secondary issue in the way the transitions were created – too many spline points = bad curvature.

Fig. 3 The sketch is wrong

Fig. 3 The sketch is wrong

As you noticed in the video, we recreated the sketch using tangent arc and lines and fitting splines on top of them. As an alternative we could have used 2 point splines for the transition.

Alin Vargatu, CSWE

Alin est un ingénieur d'application SOLIDWORKS Elite et un contributeur avide à la communauté SOLIDWORKS. Alin a fait de nombreuses présentations lors de SOLIDWORKS World, de sommets techniques et de réunions de groupes d'utilisateurs, tout en étant très actif sur le forum SOLIDWORKS.